Method of molding



Aug. 19, 1924., 1,505,724

w. H. NICHOLS METHOD OF MOLDING Filed Nov. 1, 1922 2 Sheets-Sheet 1 ENT Aug. 19 W40 15%,724

W. H. NICHOLS METHOD OF MOLDING Filed Nov.-l, 1922. 2 sm J-sn; 2

mvmmn Patented Au 19, 1924.

UNITE STATES WILLIAM H. motions, or WILKINSBURG, PENNSYLVANIA.

METHOD OF, MOLDING.

Application filed November To all whom it may concern:

Be it known that I, lVInLmM H. NICHOLS,

a citizen of the United States, and resident of lVilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Molding; and I do hereby declare the following to be a full, clear, and exact description thereof.

My invention relates to molds for forming the necks of rolls cast in groupsor clusters, and for similar purposes, and it relates particularly to drag molds for use in casting clusters of rolling mill rolls.

The object of my invention is to provide an improved sand mold for simultaneously casting two articles having horizontal runners in line with each other andembedded inthe sand. In preparing such a mold it is a difficult matter toremove the patterns which form the runners. An important fea- I ture of my invention is the provision of a method of removing patterns from a mold of the kind described, this method consisting, in general, in providing an additional pattern which is removed after the mold is tamped and which gives access to the runner patterns. The opening or openings left by the additional pattern are then closed means of cores previously formed from molding sand or the like.

In my application for Letters Patent filed January 10, 1921, Serial No, 436,313, I

have described and claimed a novel method a metal drag'flask designed for casting four chill rolls. In 'order to receive the neck molds for the four rolls, the flask 2 is pro of casting chill rolls'consisting in arranging a plurality of molds. around a common upright pouring gate and pouring molten metal simultaneously through the'upright gate into alloi" the molds. As shown in my prior application, the chills and the upright gate-box are all mounted upon a common drag'flask in which the neck cavities, horizontal sprue-runners and the-lower end of the unright pouring gate are molded in sand'l I The present application isa continuation of my prior application No. 436,313, and is specifically concerned with the method by which the neck cavities, sprue runners and pouring gate are molded in the drag flask.

It will be understood that the principles of my present invention may be employed in making molds for other articles than rolling mill rolls andiparticularly in making molds whereintw o'or'more molding cavities 1,1922; Serial No. 598,360.

are connected by means of runners with a common pouring gate.

In the accompanying drawing, Fig. lis a vertical sectional view through a group of c-hlill molds arranged for casting rollsaccording to 'm-yabovamentioned prior application, Serial No. 436,313, and provided with a drag mold constructed according to my present invention; Fig. 2 is a plan view of the drag flask and patterns; Fig. 3- is a vertical sectional view of the drag flask and patterns shown in Fig. 2; Fig. 41 is a-verti'cal sectional view similar'to Fig. 3, showi'ngthe flask filled with sand and invertedpreparatory to removing the patterns;- Fig. 5 is another vertical sectional view similar to Figs. 3 and 4, showing the manner in which the sprue patterns are removed; Fig. 6 1s another vertical sectional view similar to F igs. 3 to 5, showing the final appearance of the mold after the patterns have been removed and the core blocks placed over the sprue runners;- Fig. 7 is a plan view of the complete drag mold shown 'insection on Fig 6; Fig. 8' is a detail plan view showing the construction of the patterns used'in molding the spru-e runners; Fig. 9 is a detail plan view showing the core blocks which are placed over the inner portions of the sprue r-umiers after the patterns have been removed and Fig. 10 is a detail showing in vertical section the relation between the core blocks and the sprue runners. In the drawlng the numeral 2 lndicates four sprue patterns, each consisting of two sections '6 "and 12, which'are made separate from thecross 10 and are adapted to be laid thereonjwhen the pattern is assembled.

Four neckpatterns 13'are also'provided for shaping the necks and couplers of the rolls,

as shown in Fig. 3, each having a pin 14 adapted to enter the openings 9' in a'follower-plate 7' which rests on the usual bumper, not shown.

In assembling the mold patterns, the flask 2 is placed in proper position n the follower plate 7, the cross is set 1n the center of the flask, the sprue patterns 6 and 12 are then laid upon the arms of the pattern member 10, as shown in Figs. 8 and 8, and the neck patterns are placed in positionat the ends of the sprue runners, with thelr pins 14 inserted in the openings 9. A little sand should be placed under the projecting sprue patterns 12, as shown at 15, Fig. 3, in order to prevent these patterns from tipping over. Molding sand is then tamped into the flask in the usual manner, care being taken that the sand shall be forced beneath the sprue patterns 12.

After the sand is tamped in the flask, the flask is inverted upon a suitable bottom plate 16, as shown in Fig. 1. The neck patterns 13 are then lifted out, and the four-armed pattern member 10 is also lifted from the sand. This leaves the sprue patterns stillembedded for a portion of their length within the sand. In order to remove these sprue patterns the inner pattern sections 6 are lifted, as shown in Fig. 5, leaving room for the outer sections 12 to be pulled lengthwise into the open space left by the four-armed pattern 10. The sections 12. are pulled horizontally one by one in the manner stated, and are lifted sidewiseand vertically from the mold.

The spaces originally occupied by the four arms of the pattern member 10 are then filled with core blocks 17 previously molded from molding sand and of proper size to fit in these openings, and covering the sprue runners 1.8, as shown in Figs. 6, 7 and 10. The neck cavities 13, are then finished and coated in the usual manner, and the drag is ready foruse as shown in Fig. 2. When the drag is assembled with the chills and upright gate box, substantially all of the upper surface of the sand is covered by these parts which prevent the sand from being forced up above the sprue runners during the pouring operation. The arms of the cross pattern 10 have their sides tapered slightly, as shown in Figs. 3, at and 10, in order that this pattern may be readily lifted from the sand, and the sides of the core blocks 17 are similarly tapered.

Fig. 1. shows the complete assembly of the group of chill molds, including the drag mold described above, chills 20, upper boxes 21,, sink heads 22, and an upright gate box 28 to the upper end of which is secured a funnel 524. The vertical opening 25 in the upright gate box is in line with the central opening 26 in the upper surface of the drag mold, and the sprue runners 18, molded in the manner described above communicate radially with this central opening 26 and enterthe neck cavities 13 tangentially in order to produce the proper swirling movement of the metal.

In the operation of the mold shown in Fig. 1 to form a group of rolls, the molten metal is brought to the mold in a ladle and is poured into the funnel 24, whence it passes down through the upright channel 25 in the upright gate box 23 and through the horizontal sprue runners 18 into the lower portions of the molds. Some of the molten metal remains in the central cavity26 and serves as a cushion to prevent the descending metal from splashing.

Itwill be observed that the sides of the sprue runners 18 converge before entering the neck cavities of the molds. This gives a nozzle eflect, causing the molten metal to be injected into the molds more forcibly than would be the case if the sprue runners were of uniform cross section throughout their length.

After the rolls are cast the chills and the upper boxes are removed and the cast rolls are lifted from the drag; Since there nothing at this time above the sprue runners 18 except molding sand, the metal which has solidfied in the horizontal runners is easily lifted from the drag, sometimes carrying with it the molding sand, and at other times breaking through the molding sand.

I claim as my invention:

1. The method of making a mold that comprises placing a pattern in a flask, laying a separate elongated pattern member upon said first-named pattern, filling said flask with sand, inverting said flask, removing said first-named pattern, and withdrawing said elongated pattern member by first moving said elongated pattern member lengthwise horizontally, and then lifting said member through the space left by said first-named pattern.

2. The method of making a mold that comprises placing apattern in a flask, laying upon the said pattern a separate elongated pattern member narrower than said first-named pattern, filling said flask with sand, inverting said flask, removing said first-named pattern, withdrawing said elongated pattern member by first moving said pattern lengthwise horizontally and then lifting said member through the space left by said first-named pattern, and then placing a previously-formed block of molding material in the space left by said firstnamed pattern member.

3. The method of making a mold that comprises placing a pattern in a flask, laying a separate and elongated pattern member upon said first-named pattern with one end ofsaid elongated pattern member projecting beyond said first-named pattern member, filling said flask .with sand. inverting said flask, removing said firstnamed pattern, and withdrawing said elongated pattern member by first moving said pattern member lengthwise horizontally and then lifting said member through the space left by said first-named pattern, and then placing a previously formed block of molding material in the space left by said firstnamed pattern member.

4. The method of making a mold that comprises placing a pattern in a flask, laying upon said pattern a separate elongated pattern composed of two members laid end to end, one of said members projecting beyond said first-named pattern, filling said flask with sand, inverting said flask, removing said first-named pattern, removing the inner section of said second pattern, and

withdrawing the outer section of said sec- 0nd pattern by first moving said section lengthwise horizontally and then lifting said member through the space left by said first-named member, and then placing a previously formed block of molding material in the space left by said first-named pattern member.

5. The method of making a mold that comprises placing in a flask a pattern member having two oppositely extending arms and a central projection between said arms, laying upon the arms of said first-named pattern member elongated pattern members, each consisting of two sections laid end to end, filling said flask with sand, inverting said flask, removing said first-named pat tern member, removing the inner sections of said elongated patterns, and removing the outer sections of said elongated patterns one by one, by first moving each outer section horizontally and then lifting it through the space left by said first-named pattern member.

6. The method of making a mold that comprises placing in a flask a pattern having four horizontal arms and a project-ion at the junction of said arms, placing upon the-horizontal arms of said pattern elongated pattern members each consisting of two sections laid end to end, the outer section of each of said elongated patterns projecting beyond the arm of said firstnamed pattern upon which it rests, filling said flask with sand, inverting said flask, removing said first named pattern member, thus exposing the inner sections of said elongated patterns and portions of the outer sections thereof, removing said inner sections through the space left by said firstnamed pattern member, and then removing said outer sections one by one by first moving each section lengthwise horizontally, and then lifting said outer section vertically.

7. The method of making a drag mold for simultaneously casting a group of chill molds that comprises placing in a drag flask a pattern member having four horizontal arms symmetrically arranged around a central vertical projection, laying upon the arms of said first-named pattern mem ber elongated sprue patterns, each consisting of two sections laid end to end, the outer ends of each outer section projecting beyond the ends of said pattern member, filling said drag flask with sand, inverting said flask, removing said four-armed pattern member, thereby exposing the inner sections and portions of the outer sections of'saidsprue patterns, lifting said in ner sections out of the flask, and withdrawing the outer sections of the said sprue patterns one by one by first moving each outer section lengthwise and horizontally, and then lifting said section through the space left by said four-armed pattern member.

In testimony whereof, I, the said VVIL- LIAM H. NICHOLS, have hereunto set my hand.

WILLIAM H. NI OHOLS. 

